PIPK. 



PIPERINE. 



date undulation belonging to the whole length of the closed tubo U 

 four times the length of the tube. Imperfect as the preceding 

 explanation is, we know of no way of applying even so much to the 

 open tube. 



It is also to be noted that the whole of the preceding theory is but 

 an approximation. The extremities of the open tube are not points of 

 absolute non-condensation and non-rarefaction, but point* at which the 

 condensations and rarefactions are least and small Similarly the node* 

 are not points in which the air is absolutely at rest, but points at which 

 the motion is least. The extensions of this theory, however, important 

 as they are in a physical point of view, are not imnntlil to that funda- 

 mental explanation of the musical phenomena of a pipe, to which 

 we have expressed our intention of confining ourselves in the present 



PIPE, a circular or square artificial channel for the conveyance of 

 watery fluids, either under pressure, or flowing freely, or for the 

 passage of icriform fluids, or of sound. According to the almost endless 

 varieties of use* to which pipes may be converted, and to the positions 

 in which they may be placed, the materials of which they are formed 

 may be modified in an equally varied manner. A few of the more 

 prominent uses, and of the more generally adopted materials, are 

 therefore all that it will be possible here to allude to, under the 

 general name of pipa. 



For the purpose of removing rain-water from buildings the ancients, 

 and even occasionally the moderns also, have resorted to the use of 

 earthenware pipes of ordinary clay baked in kilns, but of late years 

 lead, sine, or iron pipes have been used in preference either to the 

 earthen, or the stoneware pipe*. Copper pipes are commonly used for 

 the ascending pipes from force pumps ; but the distribution of water 

 horizontally is almost always effected through cast or wrought iron, lead, 

 or tin pipes. Gas is distributed through cast iron mains, wrought iron 

 service-pipes, or through small pipes of tin, or of mixed metal with a 

 tin base. The foul waters from modern houses are removed through 

 glazed stoneware drains, whilst land drainage waters are removed by 

 nunns of red earthenware pipe*. Until within a very few years the 

 whole of the water supply of our towns was carried through elm pipes ; 

 and at the present day wood is still used for conveying water in 

 agricultural districts, whilst that material is considered to be the most 

 fitted for the conveyance of such fluids as tan liquor, or the bilge 

 waters of ships. Indian rubber and gutta percha pipes are some- 

 time* used for garden and irrigation purposes ; and leather pipe* are 

 almost universally used for fire engines, or for moveable pumps, of any 

 kind. 



Smoke, hot air, and hot water are conducted through pipes or 

 channels formed, as the case may require, of ordinary bricks; of 

 moulded bricks, of glazed brick, or stoneware pipes ; or of cast or 

 wrought iron, or of copper, zinc, lead, or tin ; and in the construction 

 of boiler furnaces, of drawn brass. Sound is conveyed through metal 

 pipes, or through Indian rubber, or gutta percha tubes. 



The stoneware and cast iron pipes certainly are the most durable 

 under ground ; but the chemical natures of the fluids conveyed, and of 

 the ground itself, vary within so wide a range as to render it necessary 

 to exercise great circumspection in the choice of the materials to be 

 used. Every case must in fact be regarded on its own merits; 

 observing simply that metals are peculiarly liable to decay under the 

 continuous action of dilute acids ; and that such decay will be accele- 

 rated if any galvanic action should be superinduced. In earth, it may 

 be taken as a general rule that stoneware pipes will last longer than 

 metal one* ; that lead will last longer than cast iron, and much longer 

 than wrought iron or wood ; and that both on the score of their rapid 

 decay in such positions, and of their compressibility, the pipes made 

 from vegetable substances, such as gutta percha or Indian rubber, 

 ire very objectionable for use in the ground. [SEWERAGE ; WATEB 

 iorpLT.l 



Cast iron pipes are cast vertically in loam moulds ; wrought iron 

 pipe* are either lapwelded or brazed ; lead pipes are either soldered on 

 their longitudinal seams, or they are forced by hydraulic pressure upon 



ril, so as to ensure their perfectly homogeneous character ; tin 

 pipe*, and copper or composition pipes are usually brazed, but in 

 unimportant works their longitudinal joints may be soldered like 

 those of the lead pipes. The end joint* of cast iron pipes are either 

 made with a spigot and faucet joint, which may be either turned so as 

 to fit quite tight, or be left large enough to receive a packing of yarn, 

 white lead, and melted pig lead ; or they are made with flange joints 

 connected by means of bolt* and Washers. The ends of wrought iron 

 pipe* may be connected by means of screw couplings, or by flanges ; 

 and the end joints of the more easily soldered materials are made by 

 that process, taking care of course to provide against the irregularities 

 of contraction, or of expansion in the pipe*. It is precisely on account 

 of the play afforded by the spigot and faucet joints of cost iron pipes, 

 that they are adopted when any danger of changes of temperature 

 exist*. As it is not possible to make a screwed joint with auy 

 description of earthen pipes, those articles are always made with 

 spigot and faucet joint*. The end joints of gutto ]>ercha and of 

 Indian rubber tube* are melted, and both the longitudinal or the end 

 joints of leather pipe* are sewn or riveted ; wood pipes have turned 



" joints fitting into each other, which are sometimes crewed 



The strength of a pipe must be such as to ensure its resistance to 

 the external and internal pressures it in likely to be exposed to ; but, 

 U it should work under pressure, the internal force will be, generally 

 speaking, so much in excess of the external one, that it will suffice to 

 consider the former condition to the exclusion of the latter. The 

 usual formula for calculating the thickness of pipes is as follow* : 



the 

 per 



railing p, the pressure per square inch ; r, the radius in inches of 

 interior diameter; and r, the cohesive strength of the metal 



square inch ; then * = j-^r : Mr. Hawksley adopt* a rather simpler 



formula, namely : x = 0'18 <Jd ; in which d = the diameter in inches. 

 In practice, however, the theoretical thicknesses attained by either of 

 these formula: are exceeded, on account of the difficulty of securing good 

 sound pipes, when the thickness is very small. Stone and earthen- 

 ware pipes being usually made of large diameters, and being exposed to 

 great external pressures and jars, seem to require greater thicknesses 

 than are usually given to them ; perhaps when their diameter exceeds 

 9 inches they ought, in the present state of the arts, to be made of 

 such a thickness that the Utter dimension should be equal to j^th of 

 the diameter at least. 



Rain-water, or other metal descent-pipes are made with projecting 

 ears upon the socket ends, for the purpose of receiving the nails by 

 which they are to be fixed one above another. In these cases the end 

 joints are not required to be fitted hermetically. 



PIPE-OFFICE, or more properly the Office of the Clerk of the 

 Pipe, an ancient office in the Exchequer, abolished with that of 

 troller of the pipe, by 3 & 4 William IV., c. 99. The records of the 

 office were then transferred to the custody of the king's reiiu>iii- 

 brancer. See the Report of the Commissioners on Public Records, 

 1837, p. 198. 



PIPER, MEDICAL PROPERTIES OF. Pepper. According to the 

 analysis of Pelletier, black pepper contains an acrid soft resin, a vola- 

 tile oil, pipeline, extractive, gum, bassorine, malic, and tartaric acids, 

 salts, &c. White pepper is the same fruit deprived of its outside 

 rind. 



The odour of pepper ig probably due to the volatile oil, which is not 

 acrid ; the pungent taste is most likely owing to the resin. Pi] n-riue is 

 generally yellow, from the presence of some resin, to which it is most 

 probably indebted for its virtues, as when purified by means of ether from 

 all resin, it seems devoid of power, and the febrifuge virtue* a* 

 to it belong in reality to the acrid resin. Pepper is much more em- 

 ployed as a grateful condiment than as a medicine, and it appears to 

 be essential to the process of digestion in hot countries. Of 50,000,000 

 pounds of pepper collected, one-third only goes to Europe, the greater 

 portion being consumed by the Chinese. Its moderate use with cold 

 raw vegetables or other substances difficult of digestion is to be ap- 

 proved ; its employment in excess is hurtful to the liver, and a very 

 large dose may prove fatal, not only by exciting inflammation of the 

 stomach, but by an impression on the nervous system. Block pepper 

 readily poisons hogs. 



Whole pepper is a popular remedy against intermittent fevers, and 

 impure piperine is used beneficially in like cases. 



Piper betle and piper siriboa, besides the use of them in chewing, 

 ore also employed, in the form of the freshly expressed juice, as a 

 febrifuge medicine, and as on antispasmodic, especially against obsti- 

 nate dry coughs. 



Piper methysticum, by fermentation, yields a powerfully intoxicating 

 drink. Matico is yielded by a plant called Artanthe danyata, formerly 

 considered a species of piper. {MATICO.] 



PIPERIDINK. [PmuunJ 



PIPERINE (C M H,.N 1 1 , ). An alkaloid contained in the different 

 varieties of pepper. [Pi PER, in NAT. HIST. Div.] It was discovered 

 by Oersted in 1819^ and is best obtained by the following process. 



White pepper, coarsely comminuted, is digested in alcohol, the 

 latter recovered by distillation, and the residual extract treated with a 

 small quantity of solution of potash to remove resinous matter ; the 

 resulting impure piperine is washed with water and obtained pure by 

 one or two recrystalliaations from alcohol Piperine occurs in colour- 

 less prisms, it is insoluble in cold water, only slightly so in hot water, 

 tolerably soluble in ether, and readily so in alcohol, the essential oils, 

 and acetic acid. Heated to about 212 Fahr. it melts, and at a higher 

 temperature decomposes. Concentrated sulphuric or hydrochloric 

 acids dissolve it, and nitric acid oxidises it to a brown coloured sub- 

 stance, that dissolves in caustic potash with production of a beautiful 

 blood-red colour. 



Piperine is but a feeble base. It absorbs hydrochloric acid gas with 

 avidity, a stable hydrochlorate being formed. The chloroylatinatt 

 (CeHiiN t lt , HCI, PtCl,) forms large orange-coloured crystals, very 

 soluble in water or alcohol. 



Piptriditie (C 10 H n N) is obtained when one part of piperine is dis- 

 tilled with three parts of potash-lime. It is a light oily body that rises 

 to the surface of the distillate on the addition of solid hydrate of 

 potash. It is volatile, boiling at about 222 - 8" Fahr., colourless when 

 pure, has a powerful ammoniacal odour, and is very soluble in water. 

 Its constitution has not yet been satisfactorily ascertained ; it is usual ly 

 looked upon as ammonia in which two equivalent* of hydrogen aro 

 replaced by the diatomic radical piperyl (C 10 H 10 " or Pp"). Piperyl 



